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INL Site

Executive Summary

None of the radionuclides detected in samples collected during the third quarter of 2017 could be directly linked with INL Site activities.  Levels of detected radionuclides were no different than values measured at other locations across the western United States. All detected radionuclide concentrations were well below standards set by the U.S. Department of Energy (DOE) and regulatory standards established by the U.S. Environmental Protection Agency (EPA) for protection of public health. 

This report for the third quarter of 2017 contains results from the Environmental Surveillance, Education, and Research (ESER) Program’s monitoring of the Department of Energy’s Idaho National Laboratory (INL) Site’s offsite environment, July 1 through September 30, 2017. All sample types (media) and the sampling schedule followed during 2017 are listed in Appendix A. This report contains results for the following sample types:

    • Air, including particulate air filters, charcoal cartridges, and atmospheric moisture
    • Precipitation
    • Surface water
    • Milk
    • Lettuce
    • Grain
    • Big game

Table E-1 Summary of results for the Third Quarter of 2017.


Sample Type





Gross alpha, gross beta

In the third quarter, there was no statistical difference in gross alpha or gross beta activity between INL Site, Boundary and Distant groups for the quarter as a whole. The July and August Boundary group showed the highest concentrations, followed by the INL Site group. Although the Distant group was found with the lowest gross alpha concentrations, the differences between all the groups was very small and well within normal range. Seasonal variations appear to be the result of increased particulate concentrations in air resulting from agricultural activities and regional wildfires.

Quarterly Composite

Gamma-emitting radionuclides, 90Sr, actinides (americium and plutonium)

No 137Cs or other human-made gamma-emitting radionuclides were detected in quarterly composites.  Strontium-90 was not detected either. Amercium-241 and plutonium-239/240 were detected just above the 3s uncertainty level in the composite from the duplicate sampler at Blackfoot (but not in the composite from the primary sampler in Blackfoot). Amercium-241 was also found slightly above the 3s concentration in the composite collected from the Mud Lake sampler. The result was below the DOE Derived Concentration Standard (DCS) for americium-241.

Charcoal Cartridge


Iodine-131 was not detected in any of the 26 batches counted during the quarter.

Atmospheric Moisture



Ten of the 16 samples results showed tritium concentrations greater than the 3s uncertainty level during the quarter. No sample result exceeded the DCS for tritium in air.




14 samples were collected in the third quarter. Four of the results were greater than the 3s uncertainty. All results were within the range previously measured and were consistent with those reported across the region by the Environmental Protection Agency.

Surface Water (BLR)


Gross alpha, gross beta, tritium

Gross alpha activity was detected in all samples and Gross beta was also reported in all but one sample. The concentrations were generally similar to previous results. Tritium was also detected in three samples. Concentrations were similar to those found in atmospheric moisture and precipitation samples and were consistent with previous years.



Iodine-131, other gamma-emitting radionuclides

Forty-three milk samples were collected during the third quarter of 2017. Iodine-131 was not detected in any weekly or monthly samples during the third quarter. No other human-made gamma-emitting radionuclides were found either.



Gamma-emitting radionuclides, 90Sr

No human-made gamma-emitting radionuclides were found in any of the samples. Strontium-90 was detected in all of the samples analyzed, except the sample from Shelley which was well below the detection limit.



Gamma-emitting radionuclides and 90Sr

No human-made gamma-emitting radionuclides were detected in any grain sample.  Two of the 11 grain samples collected in 2017 contained a detectable concentration of 90Sr. A lower detection limit was achieved in 2017 and the detectable results were close to this lower limit.

Large Game Animals


Gamma-emitting radionuclides

Three game animals were sampled during the quarter. No human-made radionuclides were detected.

Radiation in Our World

Radiation has always been a part of the natural environment in the form of cosmic radiation, cosmogenic radionuclides [carbon-14 (14C), Beryllium-7 (7Be), and tritium (3H)], and naturally occurring radionuclides, such as potassium-40 (40K), and the thorium, uranium, and actinium series radionuclides which have very long half lives. Additionally, human-made radionuclides were distributed throughout the world beginning in the early 1940s. Atmospheric testing of nuclear weapons from 1945 through 1980 and nuclear power plant accidents, such as the Chernobyl accident in the former Soviet Union during 1986, have resulted in fallout of detectable radionuclides around the world. This natural and manmade global fallout radioactivity is referred to as background radiation. MORE

Radiation Exposure and Dose

The primary concern regarding radioactivity is the amount of energy deposited by particles or gamma radiation to the surrounding environment. It is possible that the energy from radiation may damage living tissue. When radiation interacts with the atoms of a given substance, it can alter the number of electrons associated with those atoms (usually removing orbital electrons). This is called ionization. MORE